The electrical precharging of an intermediate circuit is generally carried out via a resistor that is connected in. Hitherto, relays have been used for the main switches. In the future, electronic switches will increasingly be used instead of the relays.
German Patent Publication No. DE 195 46 132 A1 discloses a charging circuit that limits a turn-on current by way of a semiconductor component (e.g., MOSFET). After turn-on, a time-determining RC element of a control circuit applies a gate voltage to a gate of the semiconductor component, the gate voltage causing the semiconductor component to enter into linear operation. It is only after a delay time, which is dependent on the time constant of the RC element, that the RC element applies to the semiconductor component a gate voltage that activates the semiconductor component.